Non-Invasive Evaluation of the Kinetics of Allergic and Irritant Contact Dermatitis  Susanne Astner, Arnold C. Cheung, Francisca Rius-Díaz, Apostolos G. Doukas, Farinelli William  Journal of Investigative Dermatology  Volume 124, Issue 2, Pages 351-359 (February 2005) DOI: 10.1111/j.0022-202X.2004.23605.x Copyright © 2005 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 1 Global evolution of clinical scoring in allergic contact dermatitis (ACD) versus irritant contact dermatitis (ICD) over time the values of ACD and ICD are shown. Data of all 18 subjects are shown. Data represented are mean±standard deviation (days 2–14). ACD scores (♦), ICD scores (▴). Journal of Investigative Dermatology 2005 124, 351-359DOI: (10.1111/j.0022-202X.2004.23605.x) Copyright © 2005 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 2 Confocal features of stratum corneum (SC). (a) Confocal images of allergic contact dermatitis (ACD) and irritant contact dermatitis (ICD) at days 2, 3, and 9 after removal of the Finn chambers. Left panel with features of ACD; days 2 and 3 demonstrate normal SC features. Split image day 9 with intact and fully recovered SC on the left and individual corneocytes (arrows) on the right as present in severe ACD reactions. Right panel with features of ICD. Split image day 2 demonstrates reflectance confocal microscopy (RCM) features of SC disruption, increased nuclear brightness, typical in ICD reaction (left, arrows), and RCM image of a “tissue paper reaction” (arrowheads); on day 3, RCM demonstrates areas with superficial corneocyte demarcation, and on day 9 SC is almost completely recovered. Scale bars are 50 μm. (b) The graph illustrates the severity and evolution of selected RCM parameters (SC disruption, parakeratosis, superficial necrosis, individual corneocytes) over time. The X-axis represents individual RCM parameters, the Y-axis reflects the severity of RCM scores, and the Z-axis shows the evolution over time (days 2, 3, 4, 9). All parameters reached the level of statistical significance when comparing ACD versus ICD (p<0.05). Journal of Investigative Dermatology 2005 124, 351-359DOI: (10.1111/j.0022-202X.2004.23605.x) Copyright © 2005 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 3 Confocal features of stratum granulosum (SG). (a) Confocal images of allergic contact dermatitis (ACD) and irritant contact dermatitis (ICD) at days 2, 3, and 9 after removal of the Finn chambers. Left panel with features of ACD; days 2 and 3 with spongiosis and multichambered vesicle formation (arrows) containing small round to oval structures with a bright appearance consistent with inflammatory cells (arrowheads). Day 9 with residual spongiosis and sparse inflammatory infiltrate (arrows). Right panel with features of ICD. Split image day 2 with reflectance confocal microscopy (RCM) features of intraepidermal disruption: left shows severe spongiosis and exocytosis, right with necrosis (arrows) and inflammatory cells (arrowheads). Day 3 with microvesicle formation (arrows); on day 9 SG is almost completely recovered, with occasional inflammatory cells (arrowheads). Scale bars are 50 μm. (b) The graph illustrates the severity and evolution of selected RCM parameters (spongiosis, exocytosis) over time. The X-axis represents individual RCM parameters, the Y-axis reflects the severity of RCM scores, and the Z-axis with the evolution over time (days 2, 3, 4, 9). (c) The graph corresponds to Figure 3b and shows the level of statistical significance when comparing ACD versus ICD. *Statistical significance (p<0.05); “NS” represents data points without significant statistical difference between ACD and ICD. Journal of Investigative Dermatology 2005 124, 351-359DOI: (10.1111/j.0022-202X.2004.23605.x) Copyright © 2005 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 4 Confocal features of stratum spinosum (SS). Images of allergic contact dermatitis (ACD) and irritant contact dermatitis (ICD) at days 2, 3, and 9 after removal of the Finn chambers. Left panel illustrates features of ACD. Days 2, 3, and 9 demonstrating the presence of intraepidermal vesicles (arrows) with cellular debris and inflammatory cells (arrowheads). Right panel illustrates the features of ICD. Split image day 2 evidences two aspects of these reactions: left shows spongiosis and bright nucleoli (arrows, left), right with intraepidermal necrosis, cellular debris, detached keratinocytes, and inflammatory cells (arrowheads). Similar features on day 3. Day 9 demonstrates a fully recovered spinous layer. Scale bars are 50 μm. (b) The graph illustrates the severity and evolution of selected reflectance confocal microscopy (RCM) parameters (vesicles, prominent nucleoli, necrosis) over time. The X-axis represents individual RCM parameters, the Y-axis reflects the severity of RCM scores, and the Z-axis with the evolution over time (days 2, 3, 4, 9). (c) The graph corresponds to Figure 4b and shows the level of statistical significance when comparing ACD versus ICD. *Statistical significance (p<0.05); “NS” represent data points without significant statistical difference between ACD and ICD. Data of prominent nucleoli not shown (NS). Journal of Investigative Dermatology 2005 124, 351-359DOI: (10.1111/j.0022-202X.2004.23605.x) Copyright © 2005 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 5 The evolution of the epidermal thickness over time as evaluated by reflectance confocal microscopy (RCM). The mean values of allergic contact dermatitis (ACD), irritant contact dermatitis (ICD), and control are shown. Bars represent standard error of the mean. (days 2–14). ACD scores (♦), ICD scores (▴), and control (•). Journal of Investigative Dermatology 2005 124, 351-359DOI: (10.1111/j.0022-202X.2004.23605.x) Copyright © 2005 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 6 A typical fluorescence excitation spectrum from a volunteer of the two components produced by deconvolution (278 and 298 nm) and the residual are shown. The X-axis represents the wavelength (nm), and the Y-axis represents the relative density of signal. Journal of Investigative Dermatology 2005 124, 351-359DOI: (10.1111/j.0022-202X.2004.23605.x) Copyright © 2005 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 7 The average peak fluorescence intensity at 278 and 298 nm intensity bands from all volunteers exposed to allergen, irritant, and control over time. Error bars represent standard error of the mean. Allergic contact dermatitis (ACD) scores (♦), irritant contact dermatitis (ICD) scores (▴), and control (•). Journal of Investigative Dermatology 2005 124, 351-359DOI: (10.1111/j.0022-202X.2004.23605.x) Copyright © 2005 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 8 The evolution of transepidermal water loss measurements is shown over time, comparing mean values of allergic contact dermatitis (ACD) (♦) and irritant contact dermatitis (ICD (▴). Data represented are mean±standard deviation (days 2–14). Journal of Investigative Dermatology 2005 124, 351-359DOI: (10.1111/j.0022-202X.2004.23605.x) Copyright © 2005 The Society for Investigative Dermatology, Inc Terms and Conditions